35 to 40 saltine crackers
1 (16 ounce) package chocolate chips
1 cup butter or margarine
1 cup brown sugar
1 cup chopped walnuts (optional)

Line a greased 13 x 9-inch baking pan with crackers, one layer thick only. Melt butter in saucepan. Add brown sugar and stir until sugar is melted, blended and bubbly. Pour over crackers (crackers will float). Place in preheated 350F oven for 10 minutes.

Remove from oven. Add chocolate chips to top and spread until melted evenly over crackers. Sprinkle with nuts, if desired. Bake again for 15 minutes. Remove and let cool. Cut into squares.